Category Archives: sql

SQL – UNION vs UNION ALL Table of content UNION and UNION ALL operators are just the SQL implementation of algebraic set operators. Both of them are used to retrieve the rows from multiple tables and return them as one single table. The difference between these two operators is that UNION only returns distinct rows […]

SQL – INTERSECT Table of content In mathematical set theory, the intersection of two sets is a collection of values that are common to both sets. In real-time scenarios, there will be a huge number of tables in a database that contains information. The user may find it challenging to gather common information from various […]

SQL – EXCEPT Table of content The SQL EXCEPT Operator The EXCEPT operator in SQL is used to retrieve all the unique records from the left operand (query), except the records that are present in the result set of the right operand (query). In other words, this operator compares the distinct values of the left […]